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L1B Visa for Specialized Knowledge Workers

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The L1B visa definition of specialized knowledge is quite subjective, and can be confusing for companies wishing to take advantage of this US L1 visa, so it can be difficult to meet the requirements for the L1B specialized knowledge worker visa.

All L1B visa applicants must have spent at least 1 year in the past 3 years outside of the US working for the overseas office of the business outside the US.

L1B visa duration

L1B visas are initially granted for 3 years (if transferring the employee to an existing US office) or 1 years (if opening a new US office) extendable to a maximum of 5 years.

L1B Visa definition of specialized knowledge

Many would assume that any worker with many years of specialist experience would have specialized knowledge. While this may be true, it is not enough to meet the L1B definition of specialized knowledge. To meet the L1B definition workers must generally be key employees who have unique or rare qualifications and/or knowledge of the company's products, services, research, systems, proprietary techniques, management, or procedures that sets them apart from others in the company or industry with similar levels of experience.

It used to be the case that the US authorities only considered those with proprietary knowledge relating to their company (such as knowledge of a unique product or service) to have specialised knowledge. This is no longer the case, but such proprietary knowledge is likely to help an application.

L1B Visa evidence of specialized knowledge

For those without such proprietary knowledge applications are likely to be closely scrutinised. This means the petitioning organisation must give ample evidence that the employee's specialized knowledge is sufficiently distinguishable from others in the company and the industry at large.

Note that employees do not need have a degree to qualify for L1B visa.

Examples of evidence for L1B Specialized Knowledge

Please note that due to the subjective nature of L1B Specialized Knowledge this is not an exhaustive list. If you are unsure what evidence to provide please contact us:

  • Details of any special training the employee has undertaken, which sets them apart from other employees with similar levels of experience.

    These details should:

    • Describe the training program, including duration and completion dates, and number of hours spent in training

    • Include any certificates awarded to the employee for the program

    • Explain how the training is unique or different from that received by other employees

    • Say how many other employees have completed the same program

  • Details of any patents held by the petitioning organisation thanks to the employee's specialized knowledge

  • Details of any published material in trade or professional journals which indicate the employee's specialized knowledge

  • Details of the employee's specialized knowledge job role used to support the application.

    These details should:

    • Explain the job role, including duties, and time spent performing each duty

    • Explain how the specialized knowledge required for the position is unique or unusual within the company and industry

    • Explain the product, service, research, system, proprietary technique, management task, or procedure the role relates to

    • Explain how long it would take for an employee to gain the specialized knowledge needed for the role, including training and experience

    • Explain how the employee's work has enhanced the company's productivity, financial position, competitiveness, PR, and so on


If you would like to apply for an L1 visa through, please fill out our application form.


Further information, help, and advice's team of specialists has over 25 years of experience in immigration services, and have helped thousands of people to study and work in the US. All applications for US visas are dealt with in-house by a US qualified lawyer who is likely to be a member of the American Immigration Lawyers Association (AILA).

For more information and advice on US immigration law and US visa applications please contact us on 0344 991 9222 or at